<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
  <style>
    #p1{color: red}
    .c1{color: yellow}

    h4,#p1,.c1{background-color: blue}
    input[type="text"]{color: red}
    *{border: 1px solid purple}




  </style>

</head>
<body>
<input type="text">
<input type="password">
<p id="p1">苹果</p>
<p class="c1">香蕉</p>
<p id="p3">橘子</p>

<h3>冰箱</h3>
<h3 class="c1">洗衣机</h3>
<h3>电视机</h3>
<h4 >张三</h4>
</body>
</html>